A Genetically-Informed Study of the Causal Relationship between Fertility and Education

David Brazel , University of Oxford
Melinda Mills, University of Oxford
Felix C. Tropf, University of Oxford
Nicola Barban, University of Essex

A recent genome-wide association study of age at first sexual intercourse (AFS) and age at first birth (AFB) found genetic correlations (a measure of overlap in the effects of all common genetic variants on two traits) of 0.73 (SE = 0.02) between educational attainment (EA) and AFB and 0.61 (SE = 0.02) between EA and AFS. We use genomic structural equation models to dissect these correlations, examining the underlying causal relationships. The genetic relationship between AFB, AFS, and EA cannot be explained by the genetic components of a wide range of traits, including personality, psychiatric, reproductive, and physical measures, but age at initiation of smoking (AI), a measure of adolescent risk taking, partially mediates the correlation, as does ADHD. In this light, we suggest that the genetics of fertility and education are connected by a common link to adolescent behavioral disinhibition.

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 Presented in Session 129. Education and Fertility